WTB / WTS / WTT ADSAll Advertisements, including Want to Buy, Want to Sell, Want to Trade, Belong in the MARKETPLACE ONLY. Any new threads posted offering an item for sale, looking to trade or buy an item which are posted outside of Marketplace will be deleted without notice or warning. Existing threads will be moved to marketplace.

Marketplace Feedback RatingsThe Marketplace feedback ratings system is now back. You can now leave feedback for your Buy / Sell / Trade transactions. Instructions on how to leave feedback ratings can be found HERE

I'm also a fan of the M1A and read an article about accuracy mods from a military armorer. It might have been Art here on the board but if not it was another former military match rifle builder during the reign of the M14.
He said they would take a handfull of pistons and swap them out in a gun to see which one shoots best and there would usually be a piston that stands out from the rest.
I wonder if anybody has tried this with FAL pistons?
Could be a fun experiment?

There was a thread or two some years ago about dwell time but not much follow-up. I think the difference in the rotating bolt of the M14 and the tilting bolt of the FAL has more to do with consistency and accuracy than the dwell (just a guess on my part).

Dwell is absolutely critical to the accuracy of an autoloader... I searched for a slo mo video of a FAL firing cycle & the best one i found was at 600 frames per second... In that video it definitely appears that things are happening (ie movement) well before the projectile leaves the barrel.

Dwell is absolutely critical to the accuracy of an autoloader... I searched for a slo mo video of a FAL firing cycle & the best one i found was at 600 frames per second... In that video it definitely appears that things are happening (ie movement) well before the projectile leaves the barrel.

If thatís the case then theirs definitely room for improvement

I'm skeptical, but nonetheless interested in your results !

__________________
"The ultimate result of shielding men from the effects of folly is to fill the world with fools" Herbert Spenser

ďI respect the government only in the sense that I respect any other dangerous predator who views me as food.Ē

ďThe consolidation of the states into one vast empire, sure to be aggressive abroad and despotic at home, will be the certain precursor of ruin which has overwhelmed all that preceded it.Ē Robert E. Lee

The piston head can be machined out to form a chamber. Just have the piston head electroless nickell plated after machining, it is also a way of adjusting the head diameter to suit the I.D of the gas block.

Quote:

Originally Posted by mountainman

time to drill those pistons and compare results? Only thing I can say is those pistons are made 'out of' or 'into' unmachinableinium.

time to drill those pistons and compare results? Only thing I can say is those pistons are made 'out of' or 'into' unmachinableinium.

This - needing straight locating rods, and having hundreds of pistons, I thought it would be a good choice for scrap metal. Nope. That shit is hard. But it is selectively hard, because when Bill and I were working on a piston for the 7" FAL, we bent pistons after around 20 rds.

Rather than trying to shorten the head of the piston ?
How about the tail ?
Should be same effect and a Heck of a lot easier to do.

One could take an Stg piston, shorten it slightly in the rear, and then screw in something in the rear end and test changes in accuracy with adjustments in piston length. Measurements would have to be very precise, and the adjuster(s) screwed into the piston(s) would have to be hard as hell and impervious to peening.

I'd love to know the results of such a test and I hope someone takes the project on.

My guess is that nothing statistically significant will be obtained from a test of different dwell readings, and even less would be learned that could be extrapolated to various iterations of FALs/L1A1s. But I could be wrong, and I'd love to know if there is something I am not doing that could make my favorite FALs more accurate!

Hmm. Another thought. When Frank at POF was prototyping his gas system from my parts, I got to see a number of experimental designs. The two piece one was curious By reversing it, he chould change the gas bleed and make it suppressor capable. So maybe instead of messing with gas plug, the piston head could be modified to some form of 2-piece tappet system.

And make it lighter? But, I think you are into something: what if the bolt is made *heavier*? But then the question is how heavy it will need to be to slow it enough and what is the unintended consequence.

Quote:

Originally Posted by bykerhd

How about the tail ?
Should be same effect and a Heck of a lot easier to do.

Now you have a rod accelerating before smacking into the carrier. And against a spring which now compressed it more than it would require to push the carrier and the bolt off the locked position. I know in the G43 this is a great way to break bolt carriers.

Quote:

Originally Posted by bykerhd

I would use surplus, hopefully inexpensive, Imbel or some Euro stuff.
Worry about U.S. made stuff when the experimentation is done.

Destroy the IMBEL to save the Century Arms ones!

__________________All I'm really asking for here is a knife that will not jam and a unicorn that doesn't need sharpening. Will_PowerIt's been my experience that all you really need to harvest a deer is a car. They come right through the windshield just fine.357rossThat poop is priceless.MFC

Dwell is absolutely critical to the accuracy of an autoloader... I searched for a slo mo video of a FAL firing cycle & the best one i found was at 600 frames per second... In that video it definitely appears that things are happening (ie movement) well before the projectile leaves the barrel.

I would think the first step in scientifically approaching this would be to switch the gas plug to Grenade function, then see if it improves the group at all firing single shot. No piston movement, no bolt unlocking, etc.

If no major improvement in accuracy, well then no fiddling with the gas system dwell time issue would be worth chasing in my opinion.

may not be the correct place to post this,but, I'm looking at a pile of gas pistons and only one is hollow and threaded on the end that contacts the carrier I suspect stg,but I have no idea if that is correct. in addition to finding out which rifle this piston was used in, why is it threaded anyhow? ,
"I just has to know"

My most accurate FAL uses a piston and gas tube that came as a set with a virgin Argentine civilian parts kit. Both piston and tube are chromed and fit together tightly enough to retard the motion of the piston when dropped through the tube. There are too many variables with a rifle to say for sure whether that was responsible for the accuracy, though.